Morrowind. Its older (should easily runnwell on your rig), and its combat mechanics are more similar to table-talk rpgs (an attack might look like it should hit, but the game internally rolls dice to see if it beats enemy armor etc.), but its an immensely better RPG experience compared to Skyrim.

OpenMW is the most recommended way to play since its a reimplementation of the game engine, fixing various bugs and improving compatibility with modern computer systems while adding some modern features like shadows for terrain and more optimized lighting.